This invention relates generally to automatic tool changing machining centers having hydraulically actuated collet unclamping mechanisms and more particularly, to a mechanism for pressurizing the collet unclamping mechanism of a machining center.
Present day automatic tool changing tool machining centers such as are well known in the art, commonly employ a rotary driven spindle in which a cutting toolholder is retained by a set of Belleville washers or the like. To release the cutting toolholder secured in the spindle during a tool change cycle, a hydraulic cylinder secured opposite to the spindle so as to be coaxial with the toolholder, is actuated so that a ram at the end of the cylinder shaft biases the toolholder within the spindle against the Belleville springs to release the toolholder. Heretofore, a separate electrically driven hydraulic pump has been employed to pressurize the tool unclamping cylinder with hydraulic fluid. Such pumps are not only noisy, but are also expensive to purchase and to operate.
In contrast, the present invention concerns a mechanism to supply a hydraulic fluid to the machining center tool unclamping hydraulic cylinder which obviates the need for an electrically driven hydraulic pump.
It is an object of the present invention to provide an improved apparatus for pressurizing the collet unclamping mechanism of a machine center.
It is another object of the present invention to provide an improved apparatus for pressurizing the collet unclamping mechanism of a machining center which obviates the need for an electrically driven hydraulic pump.